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authorMike Rapoport <rppt@linux.ibm.com>2021-05-17 21:50:08 +0300
committerMike Rapoport <rppt@linux.ibm.com>2021-06-30 11:39:00 +0300
commita4d5613c4dc6d413e0733e37db9d116a2a36b9f3 (patch)
treed1c1b87b229ef3ef31accdd99bd643476b1be4e6
parent023accf5cdc1e504a9b04187ec23ff156fe53d90 (diff)
arm: extend pfn_valid to take into account freed memory map alignment
When unused memory map is freed the preserved part of the memory map is extended to match pageblock boundaries because lots of core mm functionality relies on homogeneity of the memory map within pageblock boundaries. Since pfn_valid() is used to check whether there is a valid memory map entry for a PFN, make it return true also for PFNs that have memory map entries even if there is no actual memory populated there. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Tony Lindgren <tony@atomide.com>
-rw-r--r--arch/arm/mm/init.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 9d4744a632c6..6162a070a410 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -125,11 +125,22 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
int pfn_valid(unsigned long pfn)
{
phys_addr_t addr = __pfn_to_phys(pfn);
+ unsigned long pageblock_size = PAGE_SIZE * pageblock_nr_pages;
if (__phys_to_pfn(addr) != pfn)
return 0;
- return memblock_is_map_memory(addr);
+ /*
+ * If address less than pageblock_size bytes away from a present
+ * memory chunk there still will be a memory map entry for it
+ * because we round freed memory map to the pageblock boundaries.
+ */
+ if (memblock_overlaps_region(&memblock.memory,
+ ALIGN_DOWN(addr, pageblock_size),
+ pageblock_size))
+ return 1;
+
+ return 0;
}
EXPORT_SYMBOL(pfn_valid);
#endif